The present invention relates generally to agricultural implements such as combines and, more specifically, to control of adjustments on such implements.
A modern agricultural harvester such as a combine is essentially a factory operating in the field with many interacting and complex adjustments to accommodate continually changing crop, field and machine conditions during harvest. These harvesters normally comprise a number of actuators for controlling process parameters to be set to appropriate operating positions or parameters. Generally, harvesters have controllers for automatic control of the actuators.
Solutions proposed in literature for an automatic machine adjustment have not been able to prove their value in practice. One reason for such inability is that the available sensors (as loss sensors, grain flow sensors, humidity sensors) have to be calibrated at harvest start under changing conditions. In addition, these sensors do not deliver sufficient information in order to adjust the complex system of harvesting speed, threshing cylinder rotations, concave gap, blower rotations and sieve adjustments. According to the respective harvesting conditions, the machine adjustment thus needs to be optimized for reaching the result desired by the operator in the best possible manner. The fine tuning of the machine requires much operator experience and finger tip feeling and is often very time consuming. Such tuning still has to be done by the operator.
Since the effect of different adjustments with respect to different quality criteria is often reciprocal, a number of compromises have to be made. For example, with xe2x80x9csharper threshingxe2x80x9d for improving the threshing process, the amount of damaged grain and the straw destruction can increase. With larger sieve openings for reducing cleaning shoe losses, the purity in the grain tank can get worse. The operator can influence the total harvesting performance when he defines priorities for the different quality criteria according to economical requirements.
Examples of previous harvester controllers include those with look-up tables stored in an on-board memory, such as described in U.S. Pat. No. 6,205,384. With such systems, current conditions as a group are compared to groups stored in memory. When current conditions as a group match a stored group, the stored machine settings corresponding to the conditions are used to adjust the machine. New settings can be input by an operator via keyboard. One of the problems with this approach is basically that it is an open-loop approach. Machine settings are determined by historical data stored in the look-up table rather than by control results. As a result, such an open-loop type of system provides no compensation for changes in machine, crop, fields and environments.
Another example of harvester adjustment is shown and described in U.S. Pat. No. 5,586,033 wherein the controller trains a neural network model of the harvester with data. The model is then used to determine harvester settings. The controller comprises an operator interface allowing the operator to input the relative importance of a number of criteria, as grain loss, completeness of threshing, grain damage and dockage. According to the operator-defined relative importance of the criteria and to sensor inputs, the neural network determines the adjustment of the combine working parameters. This system suffers under the lack of sufficient and exact sensor data for getting feedback. Further, neural nets in large size require a prohibitive computational effort.
It is therefore an object of the present invention to provide an improved control system for an agricultural harvester. It is another object to provide such a system which overcomes most or all of the aforementioned problems.
The control system according to the invention comprises a controller arranged to control operating parameters of adjustable crop processing means of the harvesting machine, which could be a combine or any other harvesting machine, such as a forage harvester in which, for example, the gap between a chopping drum and a shear bar could be controlled. It is proposed that an operator interface device is provided receiving an operator feedback input regarding operator satisfaction with a quality parameter of the harvesting process. The controller uses the inputted information and controls the actuator accordingly. The inputted information can be used by the controller in combination with data from sensors. When different quality parameters are inputted, the operator can define a relative importance of these parameters or a target the operator would like to achieve, as low losses or high harvesting speed. The importance of the targets could also be pre-defined. The controller considers these inputs and controls the actuators accordingly.
Thus, the control system does not rely only on sensors for obtaining feedback information on the quality of the harvesting process, which are suffering under the described disadvantages such as necessity of calibration and insufficient number of data. It would even be possible to dispense with some or all of the sensors for obtaining feedback on the harvesting process.
For an initial setup, operating parameters of the actuators can be read from a memory, preferably according to actual crop characteristics and/or harvest conditions. The latter can be inputted by the operator into the operator interface device, or measured with appropriate sensors. After a certain harvesting time has elapsed, the operator can input information about his satisfaction with the obtained results via the operator interface device. The controller considers the operator input and uses known influences, trends and/or relationships between the quality parameters of the harvesting process and necessary alterations to the actuator operating parameters. The influence, impact or trend of alterations to the parameters upon the quality parameters is known in the art and used by the controller. This process can be repeated until the operator is entirely satisfied with all quality parameters of the harvesting process, or at least the most important quality parameters are accepted.
In a preferred embodiment, the control system of the harvesting machine comprises sensors capable of gaining information on at least one quality parameter of the harvesting process. Data from the sensors and the operator feedback data are stored together. They contain information about the sensor output data and the operator""s satisfaction. For subsequent controlling purposes, the control system can, once a sufficient amount of data is stored, dispense with the operator feedback and rely on the sensor values, which are calibrated with the previously gained relationships. These relationships are preferably stored and recalled according to the respective crop characteristics and/or harvest conditions.
These and other objects, features and advantages of the invention will become apparent to one skilled in the art upon reading the following description in view of the drawings.